Introduction

 The tropical rainforest is earth's most complex biome in terms of both structure and species diversity. It occurs under optimal growing conditions: abundant precipitation and year round warmth. There is no annual rhythm to the forest; rather each species has evolved its own flowering and fruiting seasons. Sunlight is a major limiting factor. A variety of strategies have been successful in the struggle to reach light or to adapt to the low intensity of light beneath the canopy.

 Tropical rainforests contain more than half of the Earth's plant and animal species, yet cover only about 7% of the earth's land surface. A typical forest in the United States contains from 5 to 12 different kinds of trees, while a typical rainforest may have over 300 different kinds. Tropical Rainforests usually contain 10 times more tree species and 5 times more bird species than temperate forests. The Amazon forest in South America is home to more than 1600 species of birds and about a million different kinds of insects. Scientist estimate that there are at least 30,000 plant species yet to be discovered.